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UNITED STATES DEPARTMENT OF AGRICULTURE

i BULLETIN No. 1033 Ss,

Washington, D. C. PROFESSIONAL PAPER July 27, 1922

DIGESTIBILITY OF COD-LIVER, JAVA-ALMOND, TEA-
SEED, AND WATERMELON-SEED OILS, DEER FAT, AND
SOME BLENDED BYDROGENATED FATS.

By Harry J. DEvUEL, Jr., formerly junior chemist, and ArRtHuR D. HoLmsEs,
formerly specialist in charge of nutrition experiments, Office of Home
Economics, States Relations Service.

CONTENTS.
Page. Page.
Purpose of investigations ________ 1 Experiments—Continued.
REpPeriuMental. method see =o Be Watermelton-seed oil______~-__ 7
TEED] VEIN GAY 25 04 See eee PE SEES Se ko So OE dee 3 TC Si Ap Ae ees ee i led Se ae 8
GOdshiviers.Ol Ns seis fase eee Sa 3 Blended hydrogenated fats ____ 9
ava all O1 = Oi ee 5 SUITE OIE MRR eee ee 15
MCAT SCC ier OT setae oe eee hp eg de 6

PURPOSE OF INVESTIGATIONS.

An abundant supply of fat-is of major importance in the consider-
ation of nutrition, whether of the individual or the nation. Not only
are fats wholesome, palatable, and most useful in cooking, but many
also carry fat-soluble vitamin A.

Our older ideas regarding the indispensable role of fat in the diet
must be somewhat modified if we accept the results of certain recent
studies. Osborne and Mendel? conclude from experiments on rats
that “if true fats are essential for nutrition during growth, the mini-
mum necessary must be exceedingly small” and Drummond,? on
the basis of similar studies, states that unless minute amounts of fat
play as important a role in metabolism as do minute quantities of
vitamins, it is reasonable to suggest that pure fats are dispensable
constituents of the diet. Such findings, however, do not greatly
lessen the importance of fats as a foodstuff. During the recent war,

in the countries where the fat supply was far below normal, great

discomfort and a serious lowering of health and of resistance to

1 Jour. Biol. Chem., 45 (1920), No. 4, pp. 145-152.
2 Jour. Physiol., 54 (1920), No. 4, p. XXX.

105934—22

}

yah BULLETIN 1033, U. S. DEPARTMENT OF AGRICULTURE.

sod

disease were common and physiologists generally believe that this
was due, to some extent at least, to a lack of vitamin A. It should
also be remembered that fats and oils represent the most concen-
trated source of body fuel, a fact that has an important bearing on
the food transportation problem and on the. cost of food to the con-
sumer. An adequate national food policy therefore requires that an
abundant fat supply be maintained during peace times as well as
during war, and there is justification for the efforts made to find
new sources of food fats and to make better use of those we now
have.

For such reasons the Department of Agriculture has outlined a
broad program for the study of edible fats, which includes investiga-
tion of the source of supply, methods of production and rectification,
the relation of feed to fat production in farm animals, including
the cost at which fat is produced at different ages, and the relation
of this to the production of meat and dairy products. It also in-
cludes studies of the economical use of fat in cookery and its rela-
tion to the quality of the cooked product and of the thoroughness
of digestion of fats and oils and the tolerance of the body to dif-
ferent kinds. These latter aspects of the problem have been for some
years under investigation in the Office of Home Economics of the
States Relations Service, cooperation with other bureaus being se-
cured whenever this has seemed desirable.

The digestibility of 60 or more different fats and oils, some of
animal and some of vegetable origin, has been tested in the Office of
Home EKconomics. In a few cases, fish oil and avocado fat for in-
stance, the fat was not extracted but was eaten as 1¢ occurs in these
foods as ordinarily served. In most cases, however, the fat was
rendered or otherwise freed from the tissue in which it eecurs, and
if necessary, further purified. These studies have been reported
from time to time in publications of this department and in pro-
fessional journals.? This bulletin reports two groups of studies, one
with a variety of fats and oils regarding which information was
needed for special reasons, and one with blended hydrogenated fats
such as are now in common use.

EXPERIMENTAL METHOD.

The method followed in these experiments was the same as that
developed in the previous digestion experiments of this office. No
method has yet been devised by which the proportion of nutrients
actually digested from any one food material in a mixed diet can be
directly measured, and all the methods now in use admit of at least

8U. S. Dept. Agr. Buls. 310 (1915), 505 (1917), 507 (1917), 630 (1918), 687 (1918),
G13 (1919), 781 (1919) ; Jour.-Biol. Chem., 41 (920), No. 2, pp. 227-235; Amer. Jour.
Physiol., 54 (1921), No. 3, pp 479-488

‘DIGESTIBILITY OF OILS AND FATS. 3

slight chances of error through the assumptions made regarding such
factors as metabolic products and the digestibility of the nutrients
in the basal diet. The procedure here adopted is believed to give
as nearly correct results as any with which this office is familiar, and
since it has been consistently followed in all the experiments in this
laboratory, the results can be confidently said to show the relative
digestibility of the various food materials thus studied. In compar-
ing the results of studies conducted by one method with those by
another, due allowance should be made for differences in procedure
and calculation, and such allowance will frequently be found to lessen
apparent conflicts or discrepancies in the findings which different
investigators have obtained from experiments with similar materials.

The subjects in the present experiments were young men appar-
ently in normal health, most of them students in a local university.
They were familiar with this type of work, having served as sub-
jects in previous experiments, and were entirely trustworthy. Kach
experiment was carried on for three days and included nine meais.
The methods for separation of the feces, analyses, etc., were those
usually tollowed.

In each experiment the special fat to be studied was incorporated
in a cornstarch blanc-mange or pudding. This was eaten along with
a basal ration which consisted of commercial wheat biscuit, oranges,
and sugar and which supplied a very small amount of fat in com-
parison with that in the blanc-mange. Clear tea or coffee was in-
cluded when desired.

The reports of the individual experiments are here presented in
condensed form, but full data are on file in the Office of Home
Economics.

EXPERIMENTS.

COD-LIVER OIL.

Though long and favorably known in medicine, especially in the
treatment of tuberculosis and other wasting diseases, cod-liver oil has
had no general use for food purposes. It has, however, entered into
the diet to some extent, both the cod livers and the oil finding some
use as food. Dr. Vivia Appleton, who has studied diet in Labrador,
has stated in personal communications that cod livers are there con-
sidered a delicacy and she believes them to be a valuable source of
vitamin A. Fishermen from points north of Boston are said to take
the crude oil from cod livers and eat it spread on bread. The short-
age of fat and particularly milk fat, ordinarily the most important
source of vitamin A in child feeding, led Chick and Dalyell* to use

4 Brit. Med. Jour. No. 3109 (1920), pp. 151-154.

os BULLETIN 1033, U. S. DEPARTMENT OF AGRICULTURE.

cod-liver oil extensively as a food fat in the relief work with children
in Vienna after the war. The success of this makes it clear that cod-
liver oil can be relied on for such a purpose whenever circumstances
make this desirable. r

Many experimental studies of cod-liver oil have been reported in
medical literature. Some of the most interesting are those dealing
with its iodin content, which Andrés, quoted by Lewkowitsch,
reports as 0.02 for pale oil and 0.03 per cent*® for yellow oil, and to
which its therapeutic value has been attributed by some.

Osborne and Mendel ® first noted the remarkable potency of cod-
liver oil in vitamin A. More recently Zilva and Miura have shown
by new quantitative methods that crude cod-liver oil is in some cases
two hundred and fifty times as potent as butter fat and refined cod-
liver oil many times superior to butter in this respect.‘ This has
naturally aroused much interest in the relation between its vitamin
content and its therapeutic value. Such investigations, together with
its successful use in the treatment of-malnutrition in Vienna, can
hardly fail to bring about a more general use of cod-liver oil as
food fat.

It is interesting to note that cod-liver oil has been studied in
animal feeding, specifically its effect on milk production when used
as a supplement to other fat in the ration of dairy cows. Hart,
Steenbock, and Hoppert report*® that the daily addition ef from
5 to 10 cubic centimeters of cod-liver oil to the diet of dry and milk-
ing goats consistently changed negative calcium balances to positive,
showing that some factor affecting calcium assimilation is present
in cod-liver oil.

The digestibility of cod-liver oil by man has been studied by
Wells,? who fed 100 grams per day to human subjects and found that
it was well assimilated. No significant difference was noted between

the emulsified and the unemulsified oil, the coefficients of digestibility -

being respectively 96 and 97 per cent. Judging by the results ob-
tained, the cod-liver oil slightly increased the thoroughness of diges-
tion of the other fats present in the experimental ration.

In the experiments made in this laboratory no difficulty was experi-
enced in feeding the cod-liver oil, the flavor being well masked by the
caramel and vanilla extract used in the cornstarch pudding which
served as a vehicle for the fat. The results of four experiments are

summarized in Table 1.

5 Chemical Technology and Analysis of Oil, Fats, and Waxes. 1909, 4 ed., vol. 2,
p. 361.

6 Jour. Biol. Chem., 17 (1914), No. 3, pp. 401-408.

7 Lancet [London], 200 (1921), No. 5085, p. 323.

8 Jour. Biol. Chem., 48 (1921), pp. 33—50.

*’ Brit. Med. Jour. No. 2181 (1902), pp. 1222-1224.

DIGESTIBILITY OF OILS AND FATS. | 5

TABLE 1.—Summary of digestion experiments with cod-liver oil in a simple

mixed diet.
Digestibility of entire ration. Digesti-
Experiment No. Subject. cue ee
: arbo- .

Protein. Fat. hydrate. Ash. oil alone.

Per cent. | Per cent. | Per cent. | Per cent. | Per cent.
TUE gas 8 ts Es es oe ee Oe Ee GRU t sere ae, Mere 64.5 91.3 96. 4 62.0 97.2
3 EI ee aS a ees TERR Gls AR SAL eee Pe Te 65.6 96.5 C6. 6 70.4 100.0
FE Nee cy i al ee ec cpa TDs) Bech) eae eave 2 aaa ae aint ie 12.8 88. 9 §5.9 32.5 95, 2
EPA eae eee pe ee ree ee Bel Jacl eke Se eect es ae ee Pee eve | 59, 2 93.8 C6. 6 47.5 98, 4
i. Sasa isla ee eee ae aac BOG) one 96. 4 ee 97.7

The food eaten per man per day provided on an average 16 grams
of protein, 47 grams of fat, and 310 grams of carbohydrate, and its
fuel value averaged 1,740 calories. The maximum amount of cod-
liver oil consumed by any subject was 53 grams per day. The co-
efficient of digestibility was high in every case, and the average fig-
ure, 97.7 per cent, indicates a very complete utilization. Except that
all the subjects were somewhat constipated, no physiological dis-
turbance was noted.

In thoroughness of digestion, cod-liver oil agrees closely with the
majority of fats and oils that have a melting point at or below body

temperature.
| JAVA-ALMOND OIL.

The digestibility of this oi] 1s of interest not only because the nut
is valued highly in Java, but also because the finely ground kernels
mixed with water to a kind of emulsion and added to milk find there
a special use in infant feeding with, it is believed, good results.

The Java almonds (Canarium commune) needed for this experi-
ment were obtained from Java by the Office of Foreign Seed and
Plant Introduction, Bureau of Plant Industry. The nut resembles
somewhat a small-sized pecan in shape, and the kernels are much
like a small almond in appearance and have a very agreeable flavor.

In the present work a small-sized laboratory oil press was used
to express the oil, which was of clear yellow color and bland in flavor.

The supply available was sufficient for only two tests. The results
are summarized in Table 2.

TABLE 2—Summary of digestion experiments with Java-almond oil in a simple
mixed diet.

| Digesti-

Digestibility of entire ration.
| bility of
Experiment No. Subject. | Java-
F Carbo- | almond
NOUS [Ee hydrate. Ash. | oi alone.

Per cent.| Per cent. | Per cent. | Per cent. | Per cent.

“UI Beceheeers eee jae a Gre les let See 52.2 95. 5 96. 2 66.3 | $9, 4

Mek Ua atom ee sees 30.5 89.0 96.5 36. 6 94,5

INSTT ADE RA | re ase wl ey rea IS A Se ENS SENS 41.4 92. 2 96. 4 51.4 | 97.0

6 BULLETIN 1033, U. S. DEPARTMENT OF AGRICULTURE.

The food eaten per man per day provided on an average 15 grams
of protein, 61 grams of fat, and 311 grams of carbohydrate and its
fuel value averaged 1,860 calories. The average coefficient of digesti-
bility of the Java-almond oil, which made up over 98 per cent of the
total] fat of the diet, was 97 per cent. So far as may be judged by the
continued good condition of the subjects, the palatability of the oil,
and its high digestibility, there is good reason to conclude that it
compares favorably with other nut oils used in this laboratory.

TEA-SEED OIL.

The best grades of tea-seed oil are used to some extent for food
purposes in China and have been found as an adulterant of cabbage
oil. The Chinese use poorer grades for burning and for soap making.
That used in the tests here reported was a commercial product of a
pale yellow color and bland flavor.

The fitness of this by-product oil for food has been questioned on
the ground that, as saponin has been found in it, it may be harmful.
Hooper *° reports 9 per cent saponin in tea seed and states that some
is always dissolved by the oil. Weil™ states that oil made by extrac-
tion contains no saponin. The oil used in the present experiments
was eXamined for saponin in the Pharmacological Laboratory, Bu-
reau of Chemistry, with negative results.

he experiment was begun with three subjects, who ate some 40
to 50 grams of the oil per man per day. Owing to the accidental loss
of some of the feces in the case of two subjects, complete data are
available from only one person. The available results are summarized
in Table 3.

TABLE 3.—Data of digestion experiments with tea-seed oil in a simple mixed diet.

=
Digestibility of entire ration.

LU U2 eS es eee Jo iCU e235. Be a 47.2 88. 2 98. 4 | 42.1 91.2

The daily food of the subject for whom the experimental data are
complete, provided-on an average 9 grams of protein, 50 grams of
fat, and 204 grams of carbohydrate, and its fuel value averaged
1.300 calories. The average amount of tea-seed oil eaten daily was
49 grams. The subject remained in his usual good health and suf-
fered no noticeable physiological disturbances. This was equally

20 Pharm. Jour. and Trans. [London], 3. ser., 25 (1895), No. 1282, p. 605.
22 Arch. Pharm., 239 (1901), No. 5, pp. 365.

DIGESTIBILITY OF OILS AND FATS. (!

true for the two other subjects, both of whom ate the experimental
| diet for three days. The coefficient of digestibility, 91.2 per cent,
| obtained in the one complete test is somewhat lower than is
! usual with oils liquid at body temperature, but the data are too
limited to be taken as conclusive. All that can fairly be said on the
| 6 basis of the work here reported is that tea-seed oil appeared to be
well tolerated and over 90 per cent digested.

WATERMELON-SEED OIL.

Watermelon-seed oi] is at present made only for experimental
purposes, but its possible economic and commercial importance is
suggested by the fact that another cucurbit fat previously studied,
pumpkin-seed oil, is well known as a food product. It was there-
fore included in the present series of tests.

Watermelon-seed oil is easily expressed from the seed which, ac-
cording to Lewkowitsch * will yield 40.8 per cent. It is light brown
in color and pleasing in flavor. That used in the experiments here
reported was obtained through the courtesy of F. Rabak, of the
Bureau of Plant Industry. The quantity available was limited and
so the amount supplied per day to the subjects was less than usual

in such experiments.
Tests were made with three subjects. The results are summarized

in Table 4.

TABLE 4.—Summary of digestion experiments with watermelon-seed oil in a
simple mixed diet.

The total food consumed per man per day supplied on an average

9 grams of protein, 32 grams of fat of which nearly 30 grams were

| watermelon-seed oil, and 215 grams of carbohydrate, and its fuel
© value averaged 1,190 calories. No special physiological effects were
noted and the coefficient of digestibility, 94.8 per cent, was rela-
tively high. In general it can be said that watermelon-seed oil re-
sembles the two other cucurbit-seed oils previously studied, canta-

loup and pumpkin-seed oils, both of which had a coefficient of diges-

1a Chemical Technology and Analysis of Oils, Fats, and Waxes. 1909, 4. ed., vol. 2,

p. 126.

8 BULLETIN 1033, U. S. DEPARTMENT OF AGRICULTURE.

tibility of 98.2 per cent.1* Like these oils it was well tolerated and
so far as can be judged would be useful for food purposes if avail-
able commercially.

DEER FAT.

While the fat of the various species of deer is not a commercial
product in the United States, in some localities it is a constituent of
the human dietary, especially during the open season. In this con-
nection it is interesting to recall that in Alaska the carcass as well
as the milk of the reindeer is used for food and reindeer fat forms
no inconsiderable part of the diet. The importance of caribou fat
in the diet of natives-and others in the Arctic region is weil brought
out in accounts of such travelers and explorers as Stefansson.*

For the experiments reported below two shipments of fat from
white-tailed Virginia deer were obtained through the courtesy of
John B. Burnham, president of the American Game Protective and
Propagation Association. ‘The crude deer fat was taken from a num-
ber of animals shot in New England and New York during late fall
and early winter. No information was available concerning the
part of the body from which the fat was taken, but in general ap-
pearance the crude fat resembled somewhat the “leaf” or kidney
fat of mutton. The various lots received were rendered together
and the product is believed to be typical of deer fat. Its melting
point was found to be 51.4° C. This is not unlike the figures quoted
by Lewkowitsch, which show that the melting points of fat from
different species of deer vary between 49° C. and 54° C.

Only three experiments were made as the available supply of deer
fat was limited. The results are summarized in Table 5.

TABLE 5.—Summary of digestion experiments with deer fat in a simple
mixed diet.

| |
Digestibility of entire ration.

The food eaten per man per day provided on an average 25 grams

of protein, 46 grams of fat, and 311 grams of carbohydrate, and its
fuel value averaged 1.760 calories. The diet as a whole was well

13 U. S. Dept. Agr. Bul. 781 (1919).

14 My Life with the Eskimo. 1913.

16 Chemical Technology and Analysis of Oils, Fats, and Waxes. 1909, 4. ed., vol. 2,
pp. 723, 724.

DIGESTIBILITY OF OILS AND FATS. 9

assimilated, no physiological disturbance was noted, and the deer
fat, though its melting point is rather high as compared with common
food fats, did not lower the digestibility of the other ingredients of
the diet. :

The average figure reported for digestibility of deer fat, 81.7 per
cent, is considerably lower than that found in most of the experi-
ments made in this laboratory with fats. The only exceptions were.
hydrogenated peanut oil which had a melting point of 52.4° C. and
showed practically the same coefficient of digestibility,1® 79 per cent,
and oleo stearin which was 80.1 per cent digested.2?

Though the amount of deer fat eaten per man per day is small
compared with other fats previously studied in this laboratory, it
constituted the major portion of the total fat eaten in all three tests
and there seems no reason to doubt the accuracy of the results.

The average results of the experiments with cod-liver, Java-
almond, tea-seed, and watermelon-seed oils and deer fats are sum-
marizd in Table 6.

TABLE 6.—Summary of results of digestion experiments with certain miscel-
laneous oils and fat in a mixed diet.

Digestibility of entire ration.

Digesti-
Material tested. eee
: Carbohy- tone

Protein. Fat. anata Ash. alone.

Per cent. | Per cent. | Per cent. | Per cent. | Per cent.

Codslive rolls st a8 Sees Soe Eee eee. es 50. 5 §2.6 96. 4 53.1 97.7
OWA LINO OL OWIN A Ae ek eee eae ooo a seme eee EOoe 41.4 92.2 93. 4 51.4 97.0
TMS AESER ATOMS Be Iago OAM BEF Se! Toe 88. 2 98. 4 42.1} 91.2
Wiesbermelon=-Seedso las asses ae eee et ee 56.9 ~ 90.7 97.9 | 37.1 94.8
1D) CG teh art ead lane Nias MESSE 5 GE Sa RPS 2 52.2 73.6 95.0 44.5 81.7

BLENDED HYDROGENATED FATS.

During the last 10 or 15 years the hydrogenation process has come
prominently into use for the preparation of solid fats from liquid oils.
This procedure, although lmited in general use to those oils which
have a fairly large amount of unsaturated fatty acids, finds applica-
tion in the hardening of a number of vegetable and animal oils that are
produced in quantity. :

There are two general methods for the preparation of hydrogenated
fats. In one, all the oil is subjected to the hydrogenation process
until a fat of the desired melting point is obtained. In the other, part
of the oil is hydrogenated until a fat with a very high melting point
is obtained, which is then mixed with a sufficient amount of the un-
treated oil to give a fat of the desired melting point. In the discus-

18 Amer. Jour. Physiol., 54 (1921), No. 3, pp. 479-488.
“17U. S. Dept. Agr. Bul. 613 (1919).

10 BULLETIN 1033, U. S. DEPARTMENT OF AGRICULTURE.

sion which follows such fats are designated “ blended fats” in con-
trast to the * hydrogenated oils” made by hydrogenating the entire
quantity of oil.

It has been claimed that this blended fat is inferior in keeping quali-
ties to that produced by hydrogenation alone.*s The blending method
is, however, generally given preference because of the larger produc-
tion possible with a given equipment. Moreover. the blended fat
may supply vitamins, if any were present in the oil that is blended
with the hardened fat.

A previous paper from this laboratory reported a series of 44
experiments on corn, cottonseed, and peanut oils hydrogenated to dif-
ferent degrees of hardness.*° It was found that with the exception of
hydrogenated peanut oil melting at 52.4° C., which was 79 per- cent
digested, and corn oil melting at 50° C., which was §8.5 per cent di-
gested, the hydrogenated oils studied had coefficients of digestibility
of 92 per cent or higher. No one of them caused any observed diges-
tive disturbance nor was a decrease in the digestibility of the experi-
mental diet as a whole noted in any case. In general. the results
showed that as the melting point of the hydrogenated oil increased
the digestibility decreased, the decrease being much more marked
with those melting at over 46° C.

To determine whether or not blended fats have the same digesti-
bility as hydrogenated oils made from the same kinds of oils and hay-
ing approximately the same melting point. such blended fats were
used in the experiments here reported. They were made for the pur-
pose from the same lots of corn, cottonseed, and peanut oils used in
the earlier experiments with hydrogenated oils.*°

The hard fats used in the preparation of the majority of the
blended fats were prepared in the laboratory of Carleton Ellis by
one of the authors (H. J. D.) of this bulletin assisted by J. R. Kuhn.
The oils were completely saturated with hydrogen at 180° C. and had
a melting point, in every case, of approximately 60°-C. In the
case of the two blended cottonseed fats, with melting points of
41.3° C. and 50° C., cgtton stearin obtained from the Bureau of Ani-
mal Industry was mixed with a good grade of commercial edible
cottonseed 01] obtained from the Bureau of Chemistry. The melting
points, 1odin numbers, and proportions of hardened and untreated oil
in the fats used are shown in Table 10, page 13.

These blended fats were white, solid or practically so at room
temperature, and without any characteristic odor or taste. When
melted, their color was yellow, resembling that of tallow. If allowed

8 Rogers, A. Manual of Industrial Chemistry. 1915, 2. ed... p. 601.

12 Holmes, A. D., and Deuel, H. J., jr.,. Amer. Jour. Physiol., 54 (1921), No. 3, pp.
479-488.

20 Amer, Jour Physiol., 54 (1921), No. 3, pp. 479-488.

DIGESTIBILITY OF OILS AND FATS. }1

to cool slowly, the stearin separated out leaving a liquid layer on
top of it. When cooled quickly with continued stirring, a homogen-
ous, white compound was obtained which resembled lard.

Blended corn fats—~Ten digestion experiments were conducted
with blended corn fat, four with fat melting at 39° C. and three
each with fats meiting at 49° C. and 54° C. The results are sum-
marized in Table 7.

TABLE 7.—Summary of digestion experiments with blended corn fats in a simple
mixed diet.

The average amount of blended corn fat eaten per man per day
was 102.9 grams for the fat melting at 39°C., 105.4 grams for the fat
melting at 49° C., and 92.5 grams for the fat melting at 54° C. The
maximum amounts eaten per day were 121.2 grams of fat melting at
39° C. in experiment No. 1117, 126.2 grams of fat melting at 49° C.
in experiment No. 1130, and 103.7 grams of fat melting at 54° C. in
experiment No. 1134. The digestibility of the blended corn fat was
on an average 95.2 per cent for the 39° fat, 93.3 per cent for the 49°
fat, and 91.5 per cent for the 54° fat. The subjects experienced no
physiological disturbances during the three-day experimental periods.

The blended fat melting at 54° was somewhat better digested than
the hydrogenated corn oil melting at 50° used in the earlier experi-
ments, although the blended fat was eaten on an average in twice
as large amounts as the hydrogenated fat.

Blended cottonseed fats—Thirteen experiments are reported with
blended cottonseed fat, two each with the fat melting at 41.3° C.,
45.8° C., and 48.1° C., three with the fat melting at 50° C., and four
with the fat melting at 47.8° C. The results are summarized in

Table 8.

a2 BULLETIN 1033, U. S. DEPARTMENT OF AGRICULTURE.

Table 8.—Summary of digestion experiments with blended cottonseed fats in
a simple mixed diet.

Experiment No. point Subject. | ores

of fat. | Carbo-| Soe

| Protein. | Fat. eran seed fat

y ‘| alone.

| |
IC: | Per cent. | Per cent. | Per cent. | Per cent.
AiO edo bens cake a AVS BCU REL, BRYCE SES eRe Cae: eae Bn 57.7 92.8 94.8 | 97.8
AB eset: As ee AS io Paykel ped 5 bac ye tee | 76.8 | 91.9 96.8 95. 4
INVETAR Oc oes coe al eer oe Ac | SER er ee a Oe ne aE | 67.2 | 92.4 95.8 | 96.6
HCL fase prae seas iey aay se ses a Evid ag es geen me shee pia isch da 61.1 90.5 97.5 | 94.6
LTS Oe se aS ee ae oe a5 Sal ee Scent) eLeiee mee snk 56.4 | 93.8 96.7 | 98. 2
Average......._- tsbersigil era Win ee Ss ee 58.8 | 92.2 97.1 | 96.4
Hae MSMR EEN AUA Mere eh All Cr ay. Cayce erie cues uit | 66.6 85.4 93.5| 90.0
STIS Yo) pelo 8 pha boc AGB | ledinslipta Geog pe eae ee tee tcp ears 58.8 | 92.0 96.0 | 95.3
JT eee a Opi ieee ER Yr COPS IDNs] OY Beene a ean pe ee Goma 49.3 91.2 | 95.7 94.5
I SRI AL EN Mee ot Ds TON CU MCN fasl St aaam aROny ea ORR AF 75.4 le oe 29450 97.9 | 96.1
| | | |
Averapen str Sete: Set nso ratiea ee eOe ea 90.7 95.8) | 982
| | = SS
52s 9e Fb Pee) AG Sts | ABYSS oy vane need | 61.8 90. 2 97.5 | 93.7
VSS st ee SG Niele Oem sien Sake Cures eae eg 40.0 | 89.5 95.8 | 95.0
Averaceless a tll eee eae Hea Dae an Pyne Sues seta 50.9 89.8 95.6 | 94.4
Adib, Mog 3 SOS PER Cau ue care Paar: 76.3 96.7 | 82.6
LOL UML ea Kage S50 MIMER: DANG ea yen Wah sire ee mek G4as 85.6 97.5 | 89.9
BOK NRE TE RERAGES S SS Bi) nO HUN Sage Mille sce botnet ag 61.5 84.1 97.5 | 88.4
Uae ibe GE eemneas al Faepren Weiwe. eu o Mien Gy 2s 60.7 | 82.0 97.2 | 87.0
}

The subjects ate on an average per man per day 62.3 grams of the
fat melting at 41.3° C., 52.6 grams of the fat melting at 45.8° C., 76.3
grams of the fat melting at 47.8° C., 49.4 grams of the fat melting at
48.1° C., and 56.9 grams of the fat melting at 50° C. The maximum
eaten per day was 63.3 grams of the 41.3° C. fat, 52.8 grams of the
45.8° C. fat, 98.1 grams of the 47.8° C. fat, 53.3 grams of the 48.1°
C. fat, and 62.7 grams of the 50° C. fat. The average coefficients
of digestibility found were 96.6 per cent for the 41.3° C. fat, 96.4
per cent for the 45.8° C. fat, 94.2 per cent for the 47.8° C. fat, 94.4
per cent for the 48.1° C. fat, and 87 per cent for the 50° C. fat.
The subjects remained in normal health except for the experiments
with fat melting at 50° C. In the reports of their condition in this
case the subjects mentioned a feeling of nausea and headache. Such
conditions were not noted in the other experiments with hydrogenated
fats of high melting point and may not be directly ascribable to
the fat ingested. Similar effects had been noted in earlier experti-
ments in which cocoa fat?" and cupuasstii fat?? were eaten in large
quantities.

Blended peanut fats—Thirteen experiments were conducted with
blended peanut fat, five with fat melting at 43° C. and four each with
fats melting at 43.2° C. and 51.1° C. The results are summarized in
Table 9.

20. §. Dept. Agr. Bul. 505 (1917).

22 Jour. Biol. Chem., 41 (1920), No. 2, pp. 227-235. Cupuassi fat is expressed from
the seed of the fruit of the cupuassu tree (Theobroma grandiflora Schum).

DIGESTIBILITY OF OILS AND FATS. 13

TABLE 9.—Summary of digestion experiments with blended peanut fats in a
: simple mixed diet.

OSS ere ee ee es 43 J BO (Ose Bs See Eee peas rae | 63 3 94.2 | 96.2 98.4
US SRE ES Ce AS See hes ee 43 Wa Deets t e a Sere 71.0 | 91.5 | 98 3 94.5
OOO Rx asume aaarteacinsas 43 18 fd bet Cane See eae aon eae | 53.4 91.5 | 96.1 96.0
USES gt So Ses eee ese 43 Sygate eee Pee 61.5 3 0 97.1 96.4
O92 ya eS Sa, 43 JSR Sree aes Seaeeens CS 63.4 | 93.1 | 96 3 97.6
ey clare meee: (mcrae ie ete anata: cree 2M ah 62.5 92.7 |" 96.8 96.6

1QOSHi ee ee ing Oew oe ee Oe esse en ong yee ors 94.3
LOS eee eee eee dee IPET S Wenn De GT ea ene fen See eRe ny NS & 61.5 89.4 97.1 92.8
LINO) Se ae re ae opera E53) Lis. Rel eal esd Deli Neves 8 ee ee ee Te 56.0 87.2 97.3 90.8
TNO Deer ee siaeerpeeayee ORI ee Be Oe aes cer eae eee oe 5.8 90.8 97.7 93.2
Peranee ere ene ee ee ea pie" 65.9 89.8 97.4 | 92.8

x }

The subjects ate on an average per man per day 73.8 grams of the
fat melting at 43° C., 79.7 grams of the fat melting at 43.2° C., and
90.3 grams of the fat melting at 51.1° C. The maximum amount of
blended peanut fat eaten per man per day was 78.4 grams of the 48° C.
fat, 100.1 grams of the 43.2° C. fat, and 109.6 grams of the 51.1° C.
fat. 7

The average coefiicients of digestibility were 96.6 per cent for the
43° ©. fat, 97.4 per cent for the 43.2° C. fat, and 92.8 per cent for the
51.1° C. fat. The subjects remained in apparently normal health and
suffered no physiological disturbances.

Discussion.—A summary of the results obtained from these experi-
ments with blended fats of different melting points prepared out of
corn, cottonseed, and peanut oil 1s given in Table 10.

TABLE 10.—Summary of digestion experiments with blended vegetable fats in a
simple mixed diet.

{
Pilea Fats in blend.
er 0 . Digest-
F Melting A See
C2 perr Kind of fat. point of | Todin ibility of
ments fat. | DUM Er. | Fordened|Untreated| piendes
e | fat. Ole eect
ducted.
ENOL Per cent. | Per cent. | Per cent.
AVAL AQUOS Glass es cee at Ney Ne ae va SA Seer ory meee 39 89.7 9.1 90.9 95.2
| (ee LOS = ES teed ied ei ae Seca ee tata eR 49 84.8 25.0 75.0 §3.3
eae (GOK Jot Sole ehh Sa Rane Mes kee ee erg See 54 85.8 30.8 69.2 91.5
DEC OLbOnSCOdn eae ee ee Men ALT GI hai Sed icons al ieee ee eee eee Saar 96.6
a [ea CLO ae a ese ree: Sis te ee 45.8 84.8 12.5 eo 96. 4
Teele ae Skin sa 3 a seein can an, Caeemeaneeeo Aa 47.8 82.4 iSioie 81-2 | 94.2
7a\ ae eee CL, eae ep en Neen i Bogie ape psa 48.1 80.0 2325 76.5 94.4
al pees Oe eee ne eatoe emacs ee cme 5) (0) nee eee 22.1 | 77.9 87.0
1ayail-> ] BC ee2 fy Bil yee a se oa SL RC RCE RE 43.0 | 80.9 6.2 93.8 | 86.6
alae imei ees Ans ee eee 43.2 82.4 9.1}. , 90.9 | 97.4
re eos oes ea ee anes: es eerste 51.1 75.5 SBA |e bs Gs da 92.8

14 BULLETIN 1033, U. S. DEPARTMENT OF AGRICULTURE.

The fats studied showed coefficients of digestibility ranging from
91.5 to 97.4 per cent, except in blended cottonseed fat melting at
50° C., which gave a coefficient of digestibility of 57 per cent. It is
interesting to note that the blended fat with the highest melting
point, namely, corn fat melting at 54° C., was 91.5 per cent di-
gested, while straight hydrogenated peanut fat with a melting point &
ot 52.4° C. was found to be only 79 per cent digested.

A comparison between Table 10 and Table 11, adapted from the
report > of earlier work with hydrogenated oils of the same origin
as those used in blended form, gives an idea of the relative effect of —
the two methods of preparation upon digestibility.

TABLE 11.—Summary of digestion experiments with hydrogenated vegetable oils
in @ simple diet. e

l l

The blended fats seem to be, as a rule, slightly better utilized than
the straight hydrogenated oils melting at the same temperature.

While no definite data are available regarding the cause of higher
digestibility for blended fats, it is not without interest to suggest,
aS was done in an earlier paper, that in the process of digestion
saponification may take place only on the exterior of the particles of
hardened fat (1. e., for those melting at temperatures considerably
above that of the human body), which decrease in size as the process
of digestion continues. If surface area be thus a factor, then the rate
of digestion and possibly the extent of digestion of a hydrogenated
fat having a high melting point is governed to some extent by the
size of the particles of hydrogenated fat ingested. If this hypothesis
be tenable, it follows that particles of blended fat which are honey- (
combed with veins of a low melting fat would, after they had come to
the temperature of the body, present greater surface area than par-
ticles of straight hydrogenated oil, which present only an exterior
surface to the action of the digestive juices.

—_—
=

33 Amer. Jour. Physiol., 54 (1921), No. 3, pp. 479-488.

DIGESTIBILITY OF OILS AND FATS.

The blended fats were eaten in relatively large quantities and

caused no apparent physiological disturbances.

While the number

of experiments here reported is small, it is believed the data are
sufficient to permit the conclusion that the digestibility of these
blended fats compares favorably with that of the natural fats of
corresponding melting points.

SUMMARY OF RESULTS.

For purposes of general comparison the average results of the
preceding experiments on the digestibility of oils and fats are sum-
marized in Table 12.

TABLE 12.—A verage digestibility of oils and fats in a mixed diet.

| Melting

Kind of oil or fat. | point.
i}
|
oO
Codslivenolle ssp eee Soe alee sees
avalon d Olle see else ee
Mea -ScedrOUlee ams tee Olen ese ieee
Watermelon-seed oil........-- [ieee Lote
ID GAMA RSs 5 = ae oe ee 51.4
Blended hydrogenated fats:
CoEniiater te ee se 39.0
1D) OSE yee 23 ales 49,0
TD YO) thee ee ss at err a 54. 0

Digesti-
bility.

Per cent. ||
| Blended hydrogenated fats:

Kind of oil or fat.

Cottonseed fat

DOS es eee ees
ipeanwivla ta soe ee

point.

| Melting | Digesti-

bility.

| Per cent

In general the results obtained in these studies agree with those
reported in the other investigations made by this office on the diges-
tibility of fats and oils.

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Full text of "Digestibility of cod-liver, Java-almond, tea-seed and watermelon-seed oils, deer fat, and some blended hydrogenated fats"

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